Anomalous transport property in the single-crystal Co nanowire with superconducting electrodes

Transport measurements were made on individual single-crystal Co nanowire with four focused ion beam (FIB) deposited tungsten (W) electrodes, which are superconducting below 5 K. It was found that the 2 microns long Co nanowire shows a sharp and large resistance peak near the onset transition temperature (T$_{C})$ of W and a rapid resistance drop below T$_{C}$. The large, 50{\%} resistance drop at low temperature suggests the proximity effect from superconducting W electrodes extends to a long fraction of the ferromagnetic Co nanowire. The resistance peak is not seen in the Au nanowire with same superconducting W electrodes. Measurements on a Co nanowire contacted with FIB deposited non-superconducting Pt electrodes show no change in resistance.